Clutch plate



Aug. 29, 1956 E. E. WEMP 2,520,350

CLUTCH PLATE Original Filed Jian. 15, 1942 2 Sheets-Sheet 1 Aug. 29,1950 E. E. WEMP 2,520,350

CLUTCH PLATE Original Filed Jan. 15, 1942 2 Sheets-Sheet 2 INVENTOR.frnfs Z. Wfmp o .0/0 ,ow .0:0 .04o .050 .060 ATTORNEY Deflection inInches .Patented Aug. 29,. 1950 v CLUTCH PLATE Ernest E. Wemp, Detroit,li/ilich.

Application January 15, 1942, Serial No. 426,892, which is a division ofapplication Serial No.

191,145, February 18, 1.938.

Divided and this application November 23, 1945, `Serial No.

2 Claims. `l

This invention relates to friction members for brakes or clutches, andit has to do particularly with a construction of a disc such as may beused as a clutch driven member or a friction member of a brake.

This application is a division of application Serial No. 426,802, filedJanuary l5, 1942, now Patent No. 2,391,495, which is a division ofapplication Serial No. 191,145, filed February 18, 1938, now Patent No.2,307,006, which is a continuation in part of application Serial No.173,332 led November 8, 193'?, and now abandoned.

The invention is directed particularly to the provision of an improveddisc for use with clutches for transmitting power from internalcombustion engines, and particularly, in automotive vehicles and for useas a friction member in disc type brakes. The disc of this invention isone designed to be packed between clutch driving members or disc brakemembers and the disc is arranged so that it is capable of compression inorder to facilitate a smooth and gradual clutch and brake engagement,and a general nicety of clutch and brake action.

Among the objects of the invention is the provision of a discconstruction which is yieldably compressible and which will provide adesired or proper deiiection curve, while the yielding elements arecomprised f parts integral with the disc body. To this end theconstruction is such that the disc resists compression both by torsionor twisting of some of the portions of the disc body and by a bendingaction. Initial stages of clutch engagement, for example, may cause atorsion or twisting action, while later stages of clutch engagement maytake place during a bending action, and in this manner a deflectioncurve, which is relatively flat in the initial stages of compression andwhich rises more sharply in the later stages of clutch engagement, isprovided.

In the accompanying drawings:

Fig. 1 is a view of a clutch disc constructed in accordance with theinvention with some of the facing cut away illustrating underlying discstructure.

Fig. 2 is `a sectional view taken substantially on line 2 2 of Fig. 1.

Fig. 3 is a cross sectional view taken through the disc substantially online 3 3 of Fig. 1.

Fig. 4 is a perspective view with part of one facing cut awayillustrating the disc structure.

Fig. 5 is an elevational view of a modied form of construction with someof the facing cut away illustrating underlying disc structure.

(Cl. 192--E8) Fig. 6 is a cross sectional View taken substantially online 6 5 of Fig. 5.

Fig. 7 is a cross sectional view taken substantially on line 1-7 of Fig.5.

Fig. 8 is a cross sectional view taken substantially on line 8-8 of Fig.5.

Fig. 9 is a perspective view with one facing cut away and illustratingthe disc structure.

Fig. 10 illustrates a deflection curve obtained with the discconstructed in accordance with this invention.

Fig. l1 is a View similar to Fig. 6 illustrating another modiiied form.

The clutch member as shown herein is in the form of a driven disc ormember for a friction clutch having a hub i arranged to be splined on toa driven shaft, and a disc body member 2. The disc and hub may beconnected by a vibration dampening arrangement in the form of an annulusof coil springs 3 located in aligned openings in the disc 2, iiange t ofthe hub `and a Washer 5. The washer 5 is connected by rivets 6 to thedisc 2 so as to operate in unison therewith, the washers passing throughclearance notches 'i in the flange of the hub. Rivets 8, each with aspring washer S at one end, pass through the members as illustrated inFig. 3, and friction material ii) is disposed between the disc and hubfiange and between the washer and hub flange. Driving forces aretransmitted from the disc to the hub and vice versa through the coilsprings, and when they flex there is a spring loaded friction actionafforded by the friction material I9. This is just one form ofconstruction which may be embodied in the member between the disc bodyand hub and this construction is substantially that as shown in PatentNo. 2,042,570 of June 2, 1936.

The disc body advantageously is of spoke construction, particularly inits outer Zone. As illustrated in Fig, 1, the spokes are generallyillustrated at l i, and each having a neck I2 and an enlarged head. Thehead, as illustrated, may be visualized as having three portions,namely, a center portion I3, and lands I4 and l5 on opposite sidesthereof. A spoke of this formation is provided by slotting the disc asat I6 and providing the slots with enlarged portions or openings l1.

Each spoke has a twisted formation with the twist formation beingsubstantially centralized on` a radial line running through the centerof the portion i3 of the spoke. This center line is generallyillustrated at il in Figs. 1 and 2. At .the line A this portion of thespoke is substantially in the plane of the body of the disc and thecenter portion i3 is inclined so that it extends to opposite sides ofthe center plane. Between the center portion and each land is a bendline illustrated at is and 29, so that the lands le and i5 aresubstantially positioned in planes parallel to the plane of the disc butaxially removed to opposite sides thereof. In the actual formation ofthe spokes the bend lines do not appear to be abrupt, althoughtheoretically the bend lines occur substantially on the lines Iii and2i?. The actual appearance is a good deal like the illustration shown inFig. 2. The shading in Figs. l and 2 is slightly exaggerated todemonstrate the formation.

Two facing members are secured to the disc, one on one side and one onthe other. The facing member 2l is secured to the lands i5, as forexample, by rivets 22. It will be understood that each spoke is formedlike the one just described, so that all of the lands i5 project to thesame side of the center plane of thedisc and are in a position to besecured to the facing 2i. The facing 23 may be provided with clearanceopenings 2e for the heads of the rivets 22 and is secured by rivets 25to the lands lli, the facing 2i being provided with clearance apertures25 for the rivets 25.

It will be observed that with this construction the facings are normallyheld in axially spaced relation, but they are capable of moving towardeach other as the disc is collapsed or compressed incident to beingpacked between clutch driving members. In clutch force is transmitted tothe lands lfrom the left as Fig. 2 is viewed, and this is resisted byalike force transmitted to the lands lll from the right. This causes atwisting or torsion action on each spoke substantially around 'itscenter line. As this is continued the extreme edge portions of the landsi4 and i5 willv come into Contact respectively with the facings 2l and25. The bend line 20, however, is at this time spaced from the facing23, and the bend line i9 is spaced from the facing 2l. Continuedaddition of clutch pressure vnow tends to bend the metal, the tendencybeing to straighten the bends i9 and 28, and ultimately, if sufficientpressure is applied, these bent portions will be straightened out.During the bending action the spokes are also twisted so that thecompression is resisted by bending and torsion. It is not essential,however, that suflicient pressure be addedto completely straighten outthe bend formations.

In the form shown Vin Fig. 5 each spoke has but a single land. In thisform the hub and associated parts have the same reference charactersapplied as are used in the form shown in Figs. 1 to 4i. 'Ihe disc bodyis illustrated at 35, while the spokes are generally illustrated at 3l.Each spoke has a neck portion 32, which connects into a body portion 33on one side of which is a wing or land. Alternate spokes have wings orlands 3e while the intervening spokes have wings or lands 35. The bodyportion 33 of alternate spokes are twisted or are angularly disposed sothat the lands 3l. are positioned on one side of the center plane asillustrated in Fig. 6, and thelands the opposite side. The join to thebody portions of spokes substantially on bend lines 35 which, however,may not be abrupt, as illustrated in Fig. 6, so that the landssubstantially parallel the plane of the disc. The facing sl on one sideis secured to the lands Sli by rivets 38 and the facing 3S on theopposite side is secured to the lands 35 by rivets 4D, the facingshaving clearance holes 4I and 42 for accommodating the rivets. The edgeof the spoke 3| opposite the edge of the lands lies substantaily in theplane of the disc. The spokes are separated by cut-out portions d5,which are preferably enlarged as at 45 to obtain the desired dimensionsof the necks 32.

In this form the initial action which takes place as the clutch beginsto engage is a torsion action on the spokes, twisting them toward aposition of alignment in the plane of the disc. In other words,considering Fig. 6, the pressure on the facing Sltwists alternatespokes, tending to force the lands 34 into the plane of the disc, andthe reacting pressure on the facing 39 twists alternate spokes tendingto urge lands 35 into the plane of the disc. Ultimately, the extremeopposite edges of alternate spokes will come into contact with thefacings, with the bend formation presenting arch-like formations betweenthe facings, and as the packing pressure of the clutch is increased thetendency is to bend the metal, thus tending to straighten out the bendformation.

In designing the clutch disc the Vresistance offered by the torsionaction may be varied by varyingv the dimensions of the necks i2 and 32.In the form shown lin Fig. 1 the initial clutch engagement exertstwisting or torsion action on the necks l2; and by varying the length,width and thickness of the necks, the resistance to this torsion actionmay be governed as desired. The necks can be varied as to length andwidth by changing the shape` of the cut-out openings l1, and as tothickness by selecting clutch disc stock. In the form shown in Fig. 5,the necks 32 may be varied as to length and width by the shape of thecut-outs 4S, and, of course, by variation-in the thickness of the stock.In the form shown in Fig. 1 the necks l2 are of considerably more widththan the necks 32 in Fig. 5, and because the necks l2 are twisted byforces from two lands on opposite sides of 'the center line, whereas thenecks 32 are twisted only by one land. In some instances it may bedesirable to form the necks so that opposite edges thereof are parallelsubstantially as illustrated in Fig. 5, and in this way there is asubstantially equal distribution of stresses in the twisting of thenecks. .In Fig. I opposite edges .of the necks I2`are Ysubstantiallyparallel for a short distance, and then terminate on radii, but oppositeedges .of the neck have the same formation.

The form shown in Fig. 1 has someY advantages over that shown in Fig. 5.Each spoke is twisted by equal forces delivered to opposite lands;therefore the tendency to shift the spoke bodily out of the plane of thedisc is substantially eliminated; whereas in the form shown in Fig. 5the body of the spoke is called upon to resist forces delivered t0 itfrom one side until such time as the facings come close enough togetherso that opposite edges 0f a spoke are in Contact with one facing.Moreover, any tendency of the facings to expand or contract, due to heatvariations, are balanced out in a better manner in the form shown inFig. l, as each spoke is connected to a facing lon opposite sidesthereof; whereas in Fig. 5 each spoke is connected only to one facing.Notwithstanding these advantages which the Fig. 1 construction has overthe Fig. 5 construction, the Fig. 5 construction is nevertheless aperfectly practical type of structure capable of operating in accordancewith the invention.

t will also be observed that in both forms of the invention the spokeshave apertures formed therein. In Fig. 1 each spoke has two apertures,at Eil and 5i, located substantially in the bend formation, while thespokes shown in Fig. 5 each are apertured as at 52. The location ofthese apertures may be varied by shifting them radially inwardly oroutwardly and by so doing the strength of the beams on opposite sides ofthe apertures may be governed. The term beam is applied to thoseportions of the spokes which engage both facings and hold the facingsyieldingly spaced apart by resistance to bending. In Fig. 1, that partof the body portion I3 on one side of the center line and land lll, andthat part of the body portion I3 on the opposite side of the center lineand land l5, all lying radially outwardly of the openings 5? and 5| maybe termed a beam. The term beam is also applied to similar portionslying radially inwardly of the openings. The distance between the centerline of spoke l l and the far edge of the land la, measured adjacent theouter periphery of the disc, is greater than the distance between thecenter line of the spoke and the far edge of the wing iii measuredadjacent the neck l2. The same thing is true as to the wing l5, and thesame thing is true as to each spoke in the form shown in Fig. 5. Theapertures 5), 5l and 52, as shown, are located so as to give the outerbeam more width than the inner beam, thus to increase its strengthsubstantially proportional to its increased length. With the aperturespositioned and formed substantially as shown, the force required tocollapse the beams is about the same. If the apertures are shiftedradially outwardly, the outer beams Will be weakened and the innerstrengthened; if the apertures are shifted relatively inwardly, theinner beams will be weakened and the outer strengthened. In this mannerthe desired strength of the beams can be obtained. Moreover, since thetendency is for the beams to increase in length with increase indiameter, the spokes in Fig. l may be cut off as illustrated at 55 sothat the outer beams are kept from being too long, and the spokes shownin Fig. 5 may be cut oif as illustrated at 56 for the same purpose.

In a cushion clutch disc of this type it is desirable, as above pointedout, that initial compression takes place against a relatively lowresistance but wherein the resistance increases as the compression ofthe disc continues. A curve plotted to show this desired characteristicis one which is fairly dat in the early stages of clutch engagement andsuch a curve is illustrated in Fig. 10, this curve being plotted from adisc constructed in accordance with Fig. 5. Here it will be noted thatthe curve is fairly fiat initially, and in fact a load of about 300 lbs.causes a deflection of about .040 of an inch. At about 1300 lbs. ofload, the deflection has increased to .060 of an inch, it being apparentthat the nnal thousand lbs. of load increased the deflection only about.021) of an inch. The present construction accomplishes this result inan admirable fashion because in initial clutch engagement the deflectionis caused by twisting of the spokes as the facings shift toward eachother. Ultimately the spokes of bend formation will be packed betweenthe facings and then upon the application of increased clutch pressurethe tendency is to straighten out the spokes. The initial torsion andthe iinal bending merge into each other to form such a curve as isplotted in Fig. 10. A total deflection of about .060 of an inch as shownin Fig. 10, is about the maximum deflection desired, and in fact in manyinstances the clutch will be constructed to give a total deiiection ofless than .060 of an inch, although the curve shown illustrates thepoint in mind.

In the form illustrated in Fig. 1l, one facing is illustrated at dil andanother at di. Instead of each spoke having portions lying normally outof the center plane of the disc, only some of the spokes are thusformed, as for example, alterlate spokes, as illustrated. One facingsuch as the facing 5G is secured to spokes 62 as by means of rivets $3,and the spokes S2 lie in the plane of the disc. Alternate spokes E5@have angular portions 65 and lands GB, preferably parallel to the planeof the disc. The facing 6l is secured to the lands as by means of rivetsEl. The lands 66 and angular portion 55 merge together substan tially onbend lines E58. Each facing may have clearance apertures for the rivetsof the other as illustrated at 653 and lll. In this form the lands G5may be Gif-set relative to the center plane of the disc twice the amountof the off-set of the lands 35 and 3d of the Fig. 5 form, and the landsMaud l5 of the Fig. l form, so that the normal spacing between thefacings 5Fl and 6l is the same as the normal spacing between the facingsof the other forms.

The spokes i take care of all of the deflection. In the irst action ofclutch engagement the portions 55 are twisted and then when the ffacings are brought close enough together so that the spokes Effi act asbridges, they are flattened by the bending action along the bend lines53. This structure also has an advantage in that the edges of the spokeslill, as indicated at li, engage across the facing 5i?. When pressure isapplied to the lands SES the cantilever action tending to bend thespokes laterally `of the plane of the disc is resisted by the contact atll. The shape and dimensions of these spokes may be designed to give therequired engagement curve as above discussed in connection with theother forms. The spokes 64 in this form may be shaped substantially likethe spokes 33 in Fig. 5, that is with an extension on one side formingan enlargement, but the spokes at 62 may or may not have enlarged heads.

In all of the forms a good wear pattern on the facings is providedbecause of the many points of support given to the facings and becausethe supports extend substantially completely across the facings from theinner to the outer peripheral edges. The clutch disc shown in Fig. 1 hasnine spokes for example. This gives nine initial supporting lands foreach facing with the supports alternating on the facings and thesupports extending substantially completely across the facings. In Fig.5 where there may be eighteen spokes, for example, there are nineinitial supports for each facing. rlhe spoke heads of all forms act asunits or in their entirety as differentiated from struck--out tongues orportions, and this contributes to the obtaining of a satisfactory wearpattern. As the spokes twist the entire head portions function on thefacings. As the spokes bend the entire head portions bend. In thismanner there are no localized points or spots which initially supportthe facings and which would be designed to give a bad wear pattern.

It will therefore be seen that the invention '7 provides a cushionclutch member which, by coinbining a torsion `action and a bendingaction, obtains a desired deflection curve and at the same time this -isaccomplished without the use of separate spring inserts. ln fact, aminimun number of parts are required, namely, the disc its-elfi and twoiaoings. Of course, the invention can be used without `the vibrationdampening hub construction, in which event the disc 2 may be fasteneddirectly to the hub i. If a torsion action alone is employed theresistance to total deflection is not adequate where the disc 2 is madeof the desired stock; in other words, if torsion alone is employed thedisc 2 will have to be made of heavier, stronger stock. Thus theinvention not only provides a structure wherein a desired ninety ofderction is obtained, but at the same stroke provides a clutch memberessentially .si ,pie in construction and composed of a minifmurn numberof parts.

l claim: l. A clutch member comprising, a disc havg L shaped spokes inits outer zone with the free ends of the horizontal portions of the L ofalternate spokes constituting lands and being disposed on alternatesides of the center plane of the disc and connected to the remainingparts of the horizontal portions of the L. substantially on bend lines,a facing on each side of the disc with the iacings connected toalternate lands, cach spoke having an aperture therein cutting acrossthe bend line to define a bent beam outwardly of the aperture and a bentbeam inwardly of the aperture, the outer beams being of greater 'cgththan the inner beams said apertures beg' located to give the outer beamsa greater width than the inner beams.

2. A clutch member comprising an inner disclilze body, a plurality ofcushion members carn ried by and disposed radially outwardly from thebody, each cushion member having a relatively narrow portion and a headportion disposed, radially outwardly from. the relatively narrowportion, the relatively narrow portion having one edge thereofsubstantially in alignment with one `edge of the head portion, saidLhead portion being enlarged circumferentially in lone directionrelative to the relatively narrow portion so that the head portionextends circumierentially beyond the other edge of the narrow portion sothat the cushion member is of vl. shape and to provide a land, a pair offriction facing rings dis posed on opposite sides of the head portionsand outwardly from the body, the head portions of the cushion membershaving a radial dimension such as to extend substantially across thewidthv of the facings, each cushion member having a substantiallyradially disposed bend line extending from a location in proximity tothe said other edge of the relatively narrow portion to the outer edgeof the head portion, the bend lines alterna cushion members beingoppositely formed so that the lands of alternate cushion members arespaced apart axially and are on opposite sides of the plane of thedisclike body, each facing ring lying Lagainst the lands of alternatespoles on, the respective side oi the center plane of the body, andmeans for connecting the facing rings respectively to the lands ofalternate cushion members, whereby, as, the facings are compressedtoward each other the cushion members yield with combined -torsion andbending actions.

ERNEST E. WEMP.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date llilfllo Spass Oct. l0, i9332,171,908 Eeringer Sept. 5, 1939 2,130,746 Salis Nov. 2l, 1939 2,195,665Wolfram Apr. 2, 1940 2,221,453 Wolfram Nov. l2, 1940 2,244,134 ThelanderJune 3, 1941 2,394,939 Tower Dec. l, (1942 2,314,948 'Nutt Mar. 39, i9432,391,495 Wemp Dec. 25, 1945

